7. Project Summary/Abstract The Day Reconstruction Method (DRM) has found widespread attention as a survey method for the measurement of daily emotional well-being experiences in large-scale population-based research. The DRM collects granular information about affective experiences as they unfold over the course of a day. Typically, the overall (?average?) level of emotions serves as an indicator of a person?s emotional well-being from the DRM. However, many aspects of people?s emotional lives are not captured by how they feel on average. The proposed application seeks to utilize the rich information inherent in the DRM for the construction of measures capturing dynamic aspects of emotional well-being, involving the intensity, frequency, variability, regulation, and complexity of a person?s everyday emotional experiences. Drawing on a rich repertoire of existing metrics of intrapersonal emotion dynamics developed in laboratory and ambulatory assessment research, we take the approach of examining whether these metrics can be successfully applied to population-level research afforded by the DRM. The psychometric properties of the new DRM metrics will be systematically evaluated and compared in a probability-based Internet panel of 1000 respondents 50 years or older, including their reliability, their correspondence with parallel indices derived from ecological momentary assessments, and their susceptibility to response style artifacts. Cognitive interviews with DRM respondents will shed light on cognitive strategies for completing the instrument that could either facilitate or impede the content validity of the new DRM metrics. To evaluate the extent to which the new DRM metrics can augment understanding of well-being and health disparities in older ages, we will examine the ability of the new DRM metrics to discriminate between demographic subgroups (age, sex, education, race/ethnicity, disability); we will further examine which of the metrics are predictive of changes in health outcomes. New metrics of emotional well- being derived from the DRM could facilitate large-scale analyses of disparities of emotional health and dysfunction, refine understanding of the development and determinants of well-being in the aging population, and augment options for evaluating policy decisions.